I'm not too familiar with the work " Demon High School DXD ". Can you provide me with more background information or storyline so that I can better understand and answer your questions?
One possible scenario in this crossover fanfiction could be the characters from D Gray - Man having to adapt to the unique supernatural environment of High School DxD. For example, Allen Walker might find himself in the middle of a battle between devils and angels in the High School DxD world. His Innocence could be perceived in different ways by the various factions there.
In general, the High School DxD anime doesn't fully adapt the light novel. Some key elements and subplots are skipped or condensed to fit the anime format. But it still manages to capture the main essence of the story.
The anime often has to condense the story from the light novel. Some details might be left out. For example, character backstories could be more in - depth in the light novel. Also, the pacing can be different. The anime may speed up certain plot points to fit within the episode time limit.
In the anime, it has vivid animations and voice acting which bring the story to life. The manga offers a more traditional comic - style experience with detailed art. The light novel, on the other hand, goes more in - depth with the story and character descriptions. For example, the anime might have to cut some minor plotlines due to time constraints, while the light novel can fully explore them.
In a Naruto and High School DxD fanfiction, there could be a scenario where the protagonists of both stories meet in a neutral dimension. Issei from High School DxD might be intrigued by Naruto's ninja skills and determination. Naruto, in turn, could be curious about Issei's Sacred Gear. They could start training together, sharing their knowledge and skills, and ultimately have to face a common enemy that threatens both their worlds.
In the light novel, the story progresses more gradually. There are more details about the characters' growth and development. For instance, Issei's journey to become stronger is more elaborately described. In the anime, some of these details are skipped to keep the story moving quickly.